Starbucks Corp on Thursday said traffic to its Americas-region stores perked up during the holiday quarter, easing investor jitters about slower growth and boosting shares more than 3 percent in after-hours trading.

Sales at Starbucks cafes open at least 13 months were up 5 percent for the U.S.-dominated Americas region in the fiscal first quarter that ended Dec. 28.

Traffic was up 2 percent, an acceleration from the 1 percent gain posted in the previous quarter. Starbucks' Americas region contributes the majority of company revenue.

Customer visits to Starbucks' Americas-region cafes had cooled for five straight quarters, causing some investors and analysts to worry that the company's increased focus on food had slowed service.

Starbucks Chief Financial Officer Scott Maw told Reuters that traffic increased steadily over the holiday quarter, which is Starbucks' most important for sales.

The world's biggest coffee chain reported quarterly net income of $983.1 million, or $1.30 per share, up from $540.7 million, or 71 cents per share, in the year-earlier quarter.

Excluding items related to its acquisition of Starbucks Japan, Starbucks earned 80 cents per share in the latest quarter.

The Seattle-based company reiterated its fiscal 2015 revenue growth forecast of 16 percent to 18 percent.

It also set its forecast for full-year earnings, excluding items, at $3.09 to $3.13 per share.

Shares in Starbucks jumped $2.65, or 3.2 percent, to $85.39 in extended trading.

(This version of the story corrects 2015 EPS outlook in the ninth paragraph)